Sasuke had been dreaming about Orochimaru for a long time now, about the immense power dangled just within his reach for once. The seal always burned a little when he woke up, still sleepy and never quite rested. When the Sound Four came, when they showed him how strong they were, he abandoned thirteen years worth of certainty with only an hour of hesitation.
The dreams had become more insistent, left a metallic taste in his mouth upon awakening, ever since Itachi came for Naruto. Came for Naruto and barely graced him with a second glance.
The sunshine must have warmed them there on the hospital roof but he hadn't felt it. Forever insignificant. The thought terrified him and had left him cold.
"You have to die once."
He couldn't go back now. He knew no happy ending would come from all of this, he knew that the past wouldn't be miraculously fixed because he killed Itachi, but he had to kill him. So he had to do this. It might be the biggest mistake of his life to leave Konoha, but it might also be the biggest mistake of his life not to.
The pill tasted raw and metallic, like his dreams.
Tomorrow would reveal if this was the best or worst thing that he could have done. But he had to do it, he had to know. He couldn't go through the rest of his life wondering if Itachi would have been dead now, if only he had accepted the snake-nin's invitation.